Laboratory mill



March 26, 1929. s. w. WIL EY LABORATORY MILL Filed Nov. 1926 ATTORNEY INVENTOR W Patented Mar. 26, 1929.

PATIENT OFFICE,

SAMUEL WILEY, F BALTIMORE, MARYLAND.

, LABORATORY MILL.

Applieatiqn filed November s, 1926. Serial No. 146,905.

The object of this invention is to devise a novel construction and arrangement of a mill which is adapted for the grinding of laboratory samples of any desired character and which is especially adapted for the proper preparation for chemical analysis of commercial products such, as drugs, fertilizers and feed stuffs, without loss of moisture from heating during preparation of the samples.

With the above and other objects in view as will hereinafter more clearly appear, my invention comprehends a novel construction and arrangement of a laboratory mill.

9 It further comprehends a novel mill wherein a portion of the grinding chamber is formed by a mesh screen, so that screens of different mesh can be interchanged. This prevents the product being treated from leaving the grinding chamber until it is re-- duced to a desired degree of fineness.

It further comprehends a novel construction of a mill, the casing of which is provided with adjustable stationary knives which co-operate with fixed knives removably carried by the rotor.

Other novel features of construction and advantage will hereinafter more clearly appear in the detailed description and the appended claims. i d

For the purposes of illustrating the in tion, I have'shown in the accompanying drawing a typical embodiment of it, which; in practice, will give reliable and satis'fac tory results. It is, however, to be understood that this embodiment 1s typical only and that the various instrumentalities of which my invention consists can be variously arranged and organized, and the invention is not, therefore, limited to the precise arrangement and organization of these instrumentalities as herein set forth.

Figure 1 is a perspective view of a laboratory mill, embodying my invention.

Figure 2 is a section on line 2-2 of Figure 1.

Figure 3 is a perspective view of one of the interchangeable screens, in detached position.

Similar numerals of reference indicate corresponding parts.

Referring to the drawings 1 designates a mill housing in which is journalled a shaft 2 which is provided with a tight and a loose pulley 3 and 4, respectively, thereby adapting it to be driven by any desired source of power.

The shaft 2 has fixed to it, in any desired manner, a knife carrying head 5. 6 designates knives carried by the head 5 and secured thereto by means of fastening devices 7. Between the knives, the head is recessed, as at 8, in order to provide a clearance for the knives, which latter are bevelled. i

9 designates a grinding caslng within which the knife 6 revolve s. This casing 9 is provided with slots 10which open into the grinding chamber 11, and in these slots are adjustable knives 12 which are provided with threaded rods 13 passing through the casing and having nuts 14. Screws 15, in threaded engagement with the casing 9, bear against the inner faces of the knives in order to secure them in fixed position. All of these screws are preferably provided with lock nuts. The stationary knives 12 are bevelled, and, in practice, I preferably employ six stationary knives which have a shearingaction with four rotatable knives.

The casing is preferably cut awa to Tovide access to the adjusting an 'loc ing screws.

The bottom of the grinding chamber is formedby means of a removable screen 17, the innerface of which conforms to the cur vature of the grinding chamber 11 and the frame of' this screen is provided with ribs 18 which are received 1n the slots 19 of the casing 9.

Interchangeable screens are employed, and,

in practice, three screens of different mesh are employed and three different sized screens are furnished with the mill, for ex- "ample a screen of one millimeter, a screen of two millimeters, and a screen of three millimeters, mesh.

The casing forms a closure for the Tear wall of the grinding section 11 and the front section is closed by means of a door 20 in the form of a flat plate which comes into close contact with the the casing 9;

This door is hinged to the casing by straps 21 and is provided with a lug 22whieh is j adapted to be received in the slot 23 of ajuxtaposed wall v locking arm 24 pivotally connected to the casing at 25 and having a set screw 26 in order that it may be tightly closed.

Beneath the screen 17 is a sliding drawer I 27 to receive the sample which has been ground. 28 designates a hopper communicating with the grinding chamber 11 and into which the material to be ground is placed.

The operation of my novel laboratory mill will be apparent to those skilled in the art and is as follows The screen of the proper mesh is inserted and the door 20 closed and locked. The material to be ground is then inserted into the hopper and passes to the grinding chamber.

s soon as material is reduced to the desired degree of fineness to pass through the screen, it is received in the drawer and the sample is then ready for testing.

It will now be apparent that I have devised a new and useful laboratory mill which embodies the features of advantage enumerated as desirable in the statement of the invention and the above description, and that while I have, in the present instance, shown and described a preferred embodiment thereof which will give in practice satisfactory and reliable results, it is to be understood that this embodiment is susceptible of modification in various-particulars without de-' parting from the spirit or scope of the inventlon or sacrlficmg any of its adyantages.

Having thus described my invention what.

ber, a laterally movable screen slidably engaging said casing and forming the lower wall of said chamber, a rotor in said chamber, knives carried by said rotor, and a door hinged to said caslng to close the open end of said chamber and prevent the removal of said screen when the door is closed.

2. A laboratory mill comprising a casing having a grinding chamber one end of which is open, adjustable stationary knives carried by, said casing,'said casing having slots, a screen forming a wallof said chamber and having a frame with ribs to engage said slots whereby screens of different mesh are interchangeable, a knife carrying rotor within said chamber, and a door closing the end of said chamber and preventing the removal of said screen when the door is in closed position.

SAMUEL W. WILEY. 

